Electrical coupling



May 23, 1939 H. J. BLAKESLEE 2,159,757

ELECTRICAL CO PLING Filed April 13, 1958 PatentedMay 23,1939

PATENT OFFICE ELECTRICAL COUPLING Henry J. Blakeslee, Marlboro, Conn., assignor to The States Company, Hartford, Conn., a corporation of Connecticut Application April 13, 1938, Serial No. 201,721

' 2 Claims. (01. 173-269) This invention relates to the construction of couplings of the closed loop or stirrup form which are designed to be attached to meter service blocks, test blocks, switch blocks, fuse blocks and other devices, for securing'thereto the terminals of line conductors.

The common coupling of this class comprises a conductor plate adapted to be attached to a supporting block and a loop which loosely encircles the plate, the loop in the interior at one end being shaped to more or less conform to the terminal to, be secured and at the other end having a screw designed to be turned against the plate in such manner as to draw the lower end of the loop toward the plate and bind the terminal between the loop and plate.

The object of the present invention is to sodesign the parts of a'c'oupllng of this type that an indifferent or careless or unskilled person will not, when the parts ,are assembled in relation of normal use insert the line terminal into the loop in such a position that the surface contact of the conductors will be inadequate and, the joint be insecure. Inattainingthis object the end of the conductor plate that is adapted to be attached to a supporting block and that extends through the loop is provided with a lug or angularly ex tending part which when the conductor plate 30 is attached to a block as in normal use so obstructs the opening through the loop that a line terminal cannot be erroneously inserted between the screw and plate but must be thrust between the plate and loop and be bound thereby when 35 the screw is turned in.

In the accompanying drawing Fig. 1 shows on enlarged scale a plan view of a coupling which embodies this invention. Fig. 2 shows a longitudinal section of the same.

Fig. 3 shows an end view. Fig. 4 shows a perspective view of one form of conductor plate which may be used. Fig. 5 shows another form of conductor plate which may be used.

Fig. 6 shows still another form of conductor plate which may be used. Fig. '7 is a sectional view of the elements with the loop arranged on the conductor plate differently from that shown in Fig. 2.

55 or less conform to the contour of the terminal The conductor plate I has a perforation 2 by 5 of a line conductor, which terminal may, of

course, be a solid wire or formed of strands of wire. vThreaded through the other end of the loop is a screw 6 which has a head so shaped that the screw may be turned against the conductor 5 plate by a screw driver or by a wrench.

The conductor plate adjacent to the .loop has a right angular bend which provides a limb I. When the loop is arranged on the main limb I of the conductor plate, as shown in Fig. 2, the limb 10 1 will obstruct the opening into the loop through which the screw passes, and when the loop is arranged on the limb l, as illustrated in Fig. 7, the main limb I of the conductor plate will obstruct the opening in the loop through which the screw 15 passes. The conductor plate shown in Fig. 5 is of different outline, but this plate has sections 8 and 9 which will obstruct part of the opening through the loop according to the location of the loop on the plate. -The conductor plate shown 20 in Fig. 6 has sections l0 and II whichwill also obstruct the opening through the loop.

With the construction described the line ter- .minal is thrust into the loop between the plate and the tapered inner wall of the loop and when the screw is turned against the plate the loop is drawn up and the terminal, whether solid wire' or stranded wire, is bound between the plate and the inner tapering walls of the lower end of the loop so that there will be a maximum amount of surface contact between the conductors, and the terminal will be securely held in place. As a resultof the bend in the plate, a terminal cannot be thrust into the'loop either longitudinally of the plate as shown in Fig. 2 or transversely of the plate as shown 'in Fig. 7, so as to be engaged by the screw when the screw is turned in. A terminal inadvertently thrust wrongly into the loop, that is, between the screw and plate, is subject to the possibility of being cut by the screw, and 40 I thereis the liability of an imperfect or loose contact being 'made, particularly should the terminal be of stranded wire which is easily crushed and spread. With the coupling provided with the simple means described herein, accidental wrong.

insertion of a terminal into a loop is impossible, and efficient contact and secure attachment is assured, as well as the possibility of arranging the loop to receive without bend the terminal of conductor entering either through the-bottom or the back of the box in which the block with the coupling is mounted.

The invention claimed is:

1. An electrical coupling designed to be attached to aservice block, which comprises a conducting loop with a screw threaded into said loop and a conducting plate bent at substantially right angles forming angularly related limbs of such size that either may be thrust into and loosely fit the opening through said loop, one of said limbs having means adapting it to be attached to a service block and provide a conducting path to a terminal on the block, the limb that is thrust into the loop being positioned to be engaged by said screw and forced toward the bottom of the loop and the other limb being positioned to extend parallel with the screw at a side of the loop and when the parts are assembled in the relation of normal use obstruct the opening into the loop between the screw and plate from the side that the conductor to be connected is normally entered into the loop.

2. An electrical coupling designed to be attached to a service block, which comprises a conducting loop with a screw threaded into said loop and a conducting plate bent at substantially right angles forming angularly related limbs of d unequal length and of such size that either may be thrust into and loosely fit the opening through said loop, the longer of said limbs being adapted to be attached to a service block and provide a conducting path to a terminal on the block, the limb that is thrust into the loop being positioned to be engaged by said screw and forced toward the bottom of the loop and the other limb being positioned to extend parallel with the screw at a side of the loop and when the parts are assembled in the relation of normal use obstruct the opening into the loop between the screw and limb of the plate that is in the loop from the side that the conductor to be connected is normally entered into the loop.

HENRY'J. BLAKESLEE. 

